73 blower motor wiring confusion

[UKPlymouth]

Guys, can you tell me whe the wiring pigtail to the blower motor fits? Is it under the dash?
I ask as on my truck and my Dart there is a 2 wire pigtail that comes off the end of the blower motor on the engine bay side of the firewall.
My Roadrunner has no such fitment showing and the blower doesn't work and I've been offerd a good one from '69 Charger which has the wires on the engine bay sound and I want to know if I can use it, thanks.

 

[UKPlymouth]

Anyone, just need to know if I can swap in a 69 Charger blower motor with the wiring connector on the engine bay side?

 

[rsd859]

No idea brother, hopefully someone will chime in. I'm ha ing blower motor problems too.

 

[73runner]

73 b body blowers have a ground and power feed (usually green but have seen red) coming from the harness along the fire wall.

hope this helps

 

[UKPlymouth]

Thanks very much 73 Runner, that has been real helpful a i don't have a factory manual to consult.
Sure looks as if the main feed from the blower exits on the engine bay side whereas my blower motor has no wires showing, hence my query.
Much appreciated!

 

[Nacho-RT74]

Blower should get one individual spade male terminal on green wire ( reds are replacement blowers ) and one eyelet terminal for ground, black wire, attached to firewall. Usually to one of the heater/AC housing studs/nuts

wire goes through engine bay allong with engine harness but attached to tranny plug ( the only cavity left on it )

When AC, Compressor clutch feeds is on the only cavity left on engine harness itself, and is dark blue

on 71s both wires were at tranny harness plug, since these didn't got the NSS ground into the cab, but 72/74s did, to the seatbelt warning system ( 71s got this light with time delay flasher control )

When AC on 74s, both wires are through wirewall with a grommet, like first pic shown, then a T plug to be attached the rest of harness, due the lack of cavities available on 74s for interlock system added wires

 

[UKPlymouth]

Just got the car back out of hibernation and thought i'd report back. Unusually, my blower motor has no wires coming out on the engine bay side nor does it seem to have a plug in facility.
Do some of these cars have a wiring set up which is all under the dash? Additionally despite the useful diagram above I can find no evidence (at first glance) of the heater motor resistor pack. All new clues welcome!

 

[73runner]

Ok..... Lets start with some basics.

Does the car have factory a/c or just the heater? Send pictures if it doesn't look like the pictures I sent or check my post on my 73 for some reference shots for the compressor etc. Send some quick pictures of what you have.

Is control panel to the left of the steering wheel? Send picture of the control panel.

We may be dealing with an aftermarket or dealer installed system.

Has your car always been in the UK?

Picture of data plate would also help confirm options etc.

 

[UKPlymouth]

Thanks for asking. The car is a South Carolina car and to my knowledge did not have AC. The heater controls are basic and to the left of the steering column. I recently saw what looked like an identical unit on ebay and it had the green feed wire on the dashboard/inside of the car.
I can get pics, may take a day or so as I have a new garage being installed tomorrow for the car as UK garages don't come in Roadrunner size as standard!

 

[73runner]

Thats a start.....

Here is the Service Manual illustrations and instructions for the heater and strato vent system.


"Strato Vent" was an option on non a/c cars and is just the two center vents. It mounts to a modified heater housing.


This is the base no charge standard heater



Looks like the blower is mounted inside the housing and accessed from inside.

Hope this gets it for you... Let us know how it goes.

 

[UKPlymouth]

Thanks so much! That is exactly what I have and recognise and that answers my questions. I have a list of things to do and this is one so I will report back in due course. I've also ordered that factory manual for my car which will be a huge help.

 

[UKPlymouth]

Time for an update. As expected, I traced the lack of power to the blower to the resistor. Now I have. A lower and a new problem instead!
Currently I cannot get the heater to turn down to cold air.
Car is basic, non AC car with no control valve on the inlet hose. I just have two water pipes (in/out) going into the bulkhead.
The lever on the far right when working under the dash is meant to adjust temp. Despite opening or closing it I can only get very hot or pretty hot air thru.
Short of blanking of the heater is there anything else to adjust?

 

[73runner]

The system you have is set up for warm and hot air only. The system allows outside air through two separate vents that lie outside the heater core air stream and are controlled at the base of the dash in the middle. These vents do not have blower motors to draw in the outside air and rely on the natural high pressure bubble at the base of the windshield that is created when the car is in motion to push the air into the cabin under the dash.

I would suggest you install a heater valve in line with your existing heater hose(s).

The stock heater valve unit for your car actually runs both hoses through the valve where the lower connection remains open regardless of the valve position.

You can get any manual valve and just insert it into the supply hose to the heater core from the water pump and install a cable control for the heater core valve to adjust the water flow to the core and thereby control the temp in the core.... Maybe put the new control cable to the valve next to the center vent controls. Or forget the control completely and just open the valve manually under the hood when it gets cold enough to merit the need for heated air.......Old school but works.

Good luck and keep us posted as I am sure there are many out there with similar problems.

 

[UKPlymouth]

Thanks, there is something I did not know again! I thought all heaters could be turned down/off irrespective of an external valve system, I thought the ducting passage would slow this.
I will do as you say and install a valve and cable system in time for winter.